This thing is awesome! I got the flags and four different inserts they are: .683, .689 .686 and the .0692. I tried blaze paintballs then tried some cheap paint, sized it of course and both paints performed the same AND did not break one ball! This is amazing! Thats not all, it was amazingly accurate! I can't say enough. It is expensive, but compared to all other brand barrels it is well worth it. I give it an A+++

Weaknesses:

Just the price, I paid 160.00. plus tax.

Conclusion:

A great product from ACI. I bought it because I like to play and to play you need paintballs and to get paintballs you need money. Well, I buy the less expensive paint and can play all day and then some with this barrel system.
TRY IT YOU'LL LIKE IT!